The present invention relates to a developer supply device to supply developer composed of powder to a developing unit provided in an image forming apparatus.
In an image forming apparatus such as a copier and printer by which an electrostatic latent image formed on a photoreceptor drum is developed by a developing device with dry and powdered developer (referred to as toner, hereinafter) so as to form a visual image, the toner provided in the developing unit is consumed each time the visual image is formed on the photoreceptor drum surface. As color copiers and printers have been developed recently, the dimensions of the apparatus have been reduced. Consequently, the developing devices of copiers and printers have been made compact. In accordance with the progress of the apparatus, the operation speed is increased and toner consumption is also increased. Therefore, it is necessary to supply toner to the developing device during image formation. In order to supply a large amount of toner as described above, a relatively large-sized toner supply device is provided separately from the developing device. In general, the toner supply device is attached above the developing device, and toner is supplied to the toner supply device before the toner in the device has been completely consumed. In this case, toner is supplied to the device from the outside when a cover of the toner supply device is slid along a groove. When new toner is supplied to the toner supply device, it is necessary to open the cover completely with respect to an opening through which toner is supplied. In order to open the cover, a large operating lever is generally provided because a long stroke is required to open the cover.
The present invention has been achieved to solve the aforementioned problems.
In order to completely open the opening of the toner supply device, a long stroke is required for the operating means. As a result, the dimensions of the device are increased, which is a problem.
In order to prevent the toner from scattering, the cover is tightly contacted with a sliding portion of the toner supply device. Therefore, strong force is required to slide the cover, so that it is very hard for an operator to slide the cover when toner is supplied.
In order to record color images, toner supply devices for 4 colors including yellow, magenta, cyan and black are required. Accordingly, when the large-sized cover sliding means is attached to each toner supply device of 4 colors, the dimensions of the entire apparatus are increased. In the case where the dimensions of the apparatus are substantially reduced, the cover can not be operated smoothly so that the operating property is lowered, which is a problem.